Ospfv3 - Avaya ERS 8800 series Configuration Manual

multicast address AllSPFRouters. On nonbroadcast multiaccess networks, some
configuration information is required to discover neighbors.
• On all multiaccess networks (broadcast or nonbroadcast), the Hello Protocol elects a
default router (DR) for the network.
• The router attempts to form adjacencies with some neighbors. On multiaccess networks,
the DR determines which routers become adjacent. This behavior does not occur if a
router is configured as a passive interface because passive interfaces do not form
adjacencies.
• Adjacent neighbors synchronize topological databases.
• The router periodically advertises the link state and changes to the local state. LSAs
include information about adjacencies to enable quick detection of dead routers on the
network.
• LSAs flood throughout the area to ensure that all routers in an area use the same
topological database.
• From the database, each router calculates a shortest-path tree, with itself as root. This
shortest-path tree yields a routing table for the protocol.

OSPFv3

This section is an overview of the differences between Open Shortest Path First (OSPF)v3
protocol, developed for IPv6, and OSPFv2, used in IPv4. This information is compiled from
RFC2740.
The IPv4 terms subnet and network are replaced in IPv6 by link. An IPv6 link is a
communication medium between nodes at the link layer. You can assign multiple IP subnets
(prefixes) to a link. Two IPv6 nodes with common or different prefixes can communicate over
a single link.
OSPF for IPv6 operates on each link rather than each subnet as in IPv4. IPv6 makes the
following changes to how packets are received and to the contents of network LSAs and hello
packets:
• The OSPF packet contains no IPv6 addresses. LSA payloads carried in link state update
packets contain IPv6 addresses.
• The following IDs remain at 32-bits and are not assigned IPv6 addresses: area IDs, LSA
link state IDs, and OSPF router IDs.
• Router IDs identify neighboring routers by an IP address on broadcast and NBMA
networks in OSPFv2.
Configuration — IPv6 Routing
OSPFv3
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